Javascript通过对象的属性过滤对象数组

Question

我有一个userList数组，其中包含用户基本信息。

this.state = {
    userList: [
        { name:"Ann", number:123456789 },
        { name:"Cathy", number:123456789 },
        { name:"Peter", number:123456789 },
        { name:"Ben", number:123456789 },
    ],
    vips: [ 
        { username:"Ann", years:2018 },
        { username:"Peter", years:2019 },
};

如何从userList返回vips？ vips.username 等于 userList.name

vips_return: [
        { name:"Ann", number:123456789 },
        { name:"Peter", number:123456789 },
]

我尝试使用 .filter 和 .includes 但我不确定如何处理对象。

const vips_return = userList.filter((user)=>
    vips.includes(user.name)
)

Answer 1

您可以使用reduce并获取userList中的用户，这些用户也在vips中

const input = {
    userList: [
        { name:"Ann", number:123456789 },
        { name:"Cathy", number:123456789 },
        { name:"Peter", number:123456789 },
        { name:"Ben", number:123456789 },
    ],
    vips: [ 
        { username:"Ann", years:2018 },
        { username:"Peter", years:2019 },
    ]
};

console.log(input.userList.reduce((acc, val) => { 
  if(!!input.vips.find(vip => vip.username === val.name)) { 
    acc.push(val);
  } 
  return acc; 
}, []));

考虑到vips的长度应该小于userList的长度，或者最大相同(vips应该是一个子集userList)，也许更好的方法是映射 VIP 并返回相应的用户，如下所示:

const input = {
    userList: [
        { name:"Ann", number:123456789 },
        { name:"Cathy", number:123456789 },
        { name:"Peter", number:123456789 },
        { name:"Ben", number:123456789 },
    ],
    vips: [ 
        { username:"Ann", years:2018 },
        { username:"Peter", years:2019 },
    ]
};

console.log(input.vips.map(vip => input.userList.find(user => user.name === vip.username)));